Individual, social, and environmental factors affecting salivary and fecal cortisol levels in captive pied tamarins (Saguinus bicolor)

Abstract

Pied tamarins (Saguinus bicolor) are endangered New World primates, and in captivity appear to be very susceptible to stress. We measured cortisol in 214 saliva samples from 36 tamarins and in 227 fecal samples from 27 tamarins, and investigated the effects of age, sex, pregnancy, rearing history, social status, weight, group composition and enclosure type using generalized linear mixed models. There was no effect of age on either fecal or salivary cortisol levels. Female pied tamarins in late pregnancy had higher fecal cortisol levels than those in early pregnancy, or nonpregnant females, but there was no effect of pregnancy on salivary cortisol. Females had higher salivary cortisol levels than males, but there was no effect of rearing history. However, for fecal cortisol, there was an interaction between sex and rearing history. Hand-reared tamarins overall had higher fecal cortisol levels, but while male parent-reared tamarins had higher levels than females who were parent-reared, the reverse was true for hand-reared individuals. There was a trend towards lower fecal cortisol levels in subordinate individuals, but no effect of status on salivary cortisol. Fecal but not salivary cortisol levels declined with increasing weight. We found little effect of group composition on cortisol levels in either saliva or feces, suggesting that as long as tamarins are housed socially, the nature of the group is of less importance. However, animals in off-show enclosures had higher salivary and fecal cortisol levels than individuals housed on-show. We suggest that large on-show enclosures with permanent access to off-exhibit areas may compensate for the effects of visitor disturbance, and a larger number of tamarins of the same species housed close Price-3 together may explain the higher cortisol levels found in tamarins living in off-show accommodation, but further research is needed.

What are you actually measuring? A review of techniques that integrate the stress response on distinct time‐scales

“…Faecal Cort is also sensitive to longer term stimuli including repeated stressors lasting days‐to‐weeks, as well as to individual differences including dominance rank, sex and age (e.g. Price et al, 2019; Table S1). Consequently, the response latency of faecal Cort metabolites is on the order of hours and they are sensitive to stressors lasting hours‐to‐weeks (Figure 1).…”

Response of Bolivian gray titi monkeys (Plecturocebus donacophilus) to an anthropogenic noise gradient: behavioral and hormonal correlates

“…Fecal glucocorticoids are expected to be less concentrated than circulating hormones, but the levels we measured in P. donacophilus are ∼200 times lower than plasma cortisol reported for P. cupreus in captivity (Hennessy et al, 1995;Ragen et al, 2013;Fisher-Phelps et al, 2015;Hostetler et al, 2016) and about ∼100 times lower than fecal cortisol measured in other Neotropical monkeys (Albuquerque et al, 2001;Ange-van Heugten et al, 2009;Wheeler et al, 2013;Cantarelli et al, 2017;Price et al, 2019). Our fresh fecal samples were immersed in aqueous alcohol solution and then transferred to a freezer.…”

“…Finally, three groups of titis had weaned infants but it is very unlikely that the females in those groupsincluding the one that provided the highest cortisol titers-were pregnant at the time of sample collection. In female tamarins, fecal cortisol has been shown to rise in late pregnancy (Bales et al, 2005;Price et al, 2019).…”

Beyond Glucocorticoids: Integrating Dehydroepiandrosterone (DHEA) into Animal Welfare Research

“…As noted above, because steroid hormones undergo metabolization in the liver and kidneys prior to excretion, fecal samples—like urine samples—yield by-products, or metabolites, of cortisol, corticosterone and DHEA(S) [ 119 , 137 ]. However, it should be noted that some researchers have specifically analyzed the native hormone, such as studies that examined fecal cortisol levels in pied tamarins [ 135 ] and scimitar-horned oryx [ 136 ].…”

“…If the sample type contains mainly metabolites of the native hormone—as with fecal samples—this test may be somewhat artificial, and the use of HPLC immunograms would be more informative [ 166 ]. Fortunately, some enzyme-linked immunosorbent assay (ELISA) test kits are successful at detecting native hormones [ 135 ]. Finally, a series of analytical validations must occur to provide evidence of assay precision and accuracy.…”